The present invention relates to a unit integrally formed of a fiber-reinforced resin, and a gas turbine stator vane structure constituted by a plurality of such units, particularly to a unit of I-shape, C-shape, etc., constituted by a fiber-reinforced core and a resin skin layer integrally molded therewith, and a gas turbine stator vane structure produced by connecting such units in a circle.
Gas turbine engines have been widely utilized for airplanes, generators of electricity, etc., because they have not only large output capacity, but also superior efficiency. Stator vanes are generally installed in a gas turbine airplane-engine to lead inhaled air into moving vanes and to rectify by-pass flow as guide vanes. The stator vanes have been generally made of metal materials such as titanium alloys, aluminum alloys, stainless steel, etc. The metal stator vane structure has been produced by forming the vanes by casting, forging, pressing, etc., and connecting the vanes to circular cases called platforms, by welding, brazing, etc.
However, the conventional metal stator vanes need machining, finishing, coating, etc., after formation, suffering disadvantages that they are completed through many working processes, some of which are extremely difficult in conducting in complicated structures, and that they are heavy and expensive because of using metal materials.
In such circumstance, the production of stator vanes composed of resins or resin composite materials has recently attracted much attention, and some proposals have been made. For example, Japanese Patent Laid-Open No. 5-278063 discloses a method for producing a stator vane made of resins comprising the steps of forming a laminate of prepregs into a vane body, which is slightly smaller than the desired size of the vane; placing the vane body in a molding die having a cavity of the final vane shape; filling a gap between the vane body and the molding die cavity with a thermoplastic resin under pressure; and carrying out compression molding. Because this method utilizes resins as materials for stator vanes, it contributes not only to reduction in production time and the weight of stator vanes and thus their cost, but also to facilitation of production steps and improvement in dimensional accuracy, etc. However, the above method is disadvantageous in that the resin-made vanes have to be fixed to platforms using adhesives, bolts, etc., to form an integral stator vane structure, requiring many components and production steps.